By default I have the same issue using KDE and a dark theme, what I do is set a specific theme inside LibreOffice. Another thing you can look for is setting another GTK theme or color scheme inside Customization on Plasma Settings
By default I have the same issue using KDE and a dark theme, what I do is set a specific theme inside LibreOffice. Another thing you can look for is setting another GTK theme or color scheme inside Customization on Plasma Settings
Use another theme, look for them in Tools->Preferences
Uninstall all the flatpak packages that are installed as system wide packages and install them as user packages, that way flatpak will use your /home partition. I had the same problem.